[Bug c++/113389] New: ICE when explicit object parameter is not declared as the first parameter

[Bug c++/113389] New: ICE when explicit object parameter is not declared as the first parameter

[cooky.ykooc922 at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113389

            Bug ID: 113389
           Summary: ICE when explicit object parameter is not declared as
                    the first parameter
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: cooky.ykooc922 at gmail dot com
  Target Milestone: ---

Although it is obviously an error, it causes ICE:

struct A {
    void foo(A, this A);
};

compiler output:
<source>:3:17: error: Only the first parameter of a member function can be
declared as an explicit object parameter
    3 |     void foo(A, this A);
      |                 ^~~~~~
<source>:3:23: internal compiler error: Segmentation fault
    3 |     void foo(A, this A);
      |                       ^
0x2640d5c internal_error(char const*, ...)
        ???:0
0xa78793 perform_implicit_conversion_flags(tree_node*, tree_node*, int, int)
        ???:0
0xb18083 check_default_argument(tree_node*, tree_node*, int)
        ???:0
0xb1861f grokparms(tree_node*, tree_node**)
        ???:0
0xb2caa1 grokdeclarator(cp_declarator const*, cp_decl_specifier_seq*,
decl_context, int, tree_node**)
        ???:0
0xb50ff3 grokfield(cp_declarator const*, cp_decl_specifier_seq*, tree_node*,
bool, tree_node*, tree_node*)
        ???:0
0xc5214a c_parse_file()
        ???:0
0xda5b49 c_common_parse_file()
        ???:0

godbolt link with -std=c++23: https://godbolt.org/z/Mxefo3nj6

[Bug c++/113389] ICE when explicit object parameter is not declared as the first parameter

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113389

Marek Polacek <mpolacek at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |mpolacek at gcc dot gnu.org
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2024-01-15

[Bug c++/113389] ICE when explicit object parameter is not declared as the first parameter

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113389

Marek Polacek <mpolacek at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
           Assignee|unassigned at gcc dot gnu.org      |mpolacek at gcc dot gnu.org

--- Comment #1 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
I have a patch.

[Bug c++/113389] ICE when explicit object parameter is not declared as the first parameter

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113389

--- Comment #2 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The trunk branch has been updated by Marek Polacek <mpolacek@gcc.gnu.org>:

https://gcc.gnu.org/g:9840e0be78150b0ef6e29975a6244698d5a5580c

commit r14-8239-g9840e0be78150b0ef6e29975a6244698d5a5580c
Author: Marek Polacek <polacek@redhat.com>
Date:   Wed Jan 17 19:16:32 2024 -0500

    c++: ICE when xobj is not the first parm [PR113389]

    In grokdeclarator/cdk_function the comment says that the find_xobj_parm
    lambda clears TREE_PURPOSE so that we can correctly detect an xobj that
    is not the first parameter.  That's all good, but we should also clear
    the TREE_PURPOSE once we've given the error, otherwise we crash later in
    check_default_argument because the 'this' TREE_PURPOSE lacks a type.

            PR c++/113389

    gcc/cp/ChangeLog:

            * decl.cc (grokdeclarator) <case cdk_function>: Set TREE_PURPOSE to
            NULL_TREE when emitting an error.

    gcc/testsuite/ChangeLog:

            * g++.dg/cpp23/explicit-obj-diagnostics10.C: New test.

[Bug c++/113389] ICE when explicit object parameter is not declared as the first parameter

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113389

Marek Polacek <mpolacek at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|---                         |FIXED

--- Comment #3 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Fixed.

[Bug c++/113389] ICE when explicit object parameter is not declared as the first parameter

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113389

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |14.0